2010-11 Stellafane Mirror Class
Session 2 held on 2011-Nov-06

Fast Class!

Well here we are in November, and the majority of our students are polishing! A very fast working class, which is great, we are looking forward to a lot of completions in the coming months, and we had three this weekend!. It's late fall in Vermont, the weather is chilly, so no outside grinding anymore - we did the grinding in our new fully enclosed pavilion area, put the polishers in the bunkhouse and the figurers in the McGregor.

Grinding in the Pavilion

A propane "bullet" heater provided warmth in the newly enclosed balcony area in the pavilion, providing a comfortable spot for our grinders. See the last row of photos below for an outside view of this space.

2010-11 Stellafane Mirror Class Session 2 held on 2011-Nov-06 Grinding in the Pavilion Before class started, instructor Ray flattens out the crown for his refractor project on a piece of plate glass.	2010-11 Stellafane Mirror Class Session 2 held on 2011-Nov-06 Grinding in the Pavilion Students begin to arrive and set up in the grinding area.	2010-11 Stellafane Mirror Class Session 2 held on 2011-Nov-06 Grinding in the Pavilion Erin & Orla at work grinding.
2010-11 Stellafane Mirror Class Session 2 held on 2011-Nov-06 Grinding in the Pavilion This is a 24" mirror with an 18" tool being ground.	2010-11 Stellafane Mirror Class Session 2 held on 2011-Nov-06 Grinding in the Pavilion Phil sprinkles on more grit.	2010-11 Stellafane Mirror Class Session 2 held on 2011-Nov-06 Grinding in the Pavilion Measuring sagitta was a bit of a challenge; clamping a yardstick to one of our 12" bar depth gauges did the trick. The level is to keep the whole rig vertical.

Polishing in the Bunkhouse

Lap making and polishing got done in the bunkhouse. Francis is polishing a set of flats, and showed us a couple of unique ways of testing the surfaces.

2010-11 Stellafane Mirror Class Session 2 held on 2011-Nov-06 Polishing in the Bunkhouse Mirror class leader Jay prepares Cerium Oxide solution before class begins.	2010-11 Stellafane Mirror Class Session 2 held on 2011-Nov-06 Polishing in the Bunkhouse Jay prepares 'a loaf' of winter pitch, custom blended for cooler temperatures.	2010-11 Stellafane Mirror Class Session 2 held on 2011-Nov-06 Polishing in the Bunkhouse Dan polishes, as does Michael in the background.
2010-11 Stellafane Mirror Class Session 2 held on 2011-Nov-06 Polishing in the Bunkhouse Leonard & Michael polish in the bunkhouse kitchen.	2010-11 Stellafane Mirror Class Session 2 held on 2011-Nov-06 Polishing in the Bunkhouse Michael trims a new lap with a precision tool made just for the job :-)	2010-11 Stellafane Mirror Class Session 2 held on 2011-Nov-06 Polishing in the Bunkhouse George & Fran chat while Fran polishes with a weight.
2010-11 Stellafane Mirror Class Session 2 held on 2011-Nov-06 Polishing in the Bunkhouse Francis with a partially cored flat he is polishing.	2010-11 Stellafane Mirror Class Session 2 held on 2011-Nov-06 Polishing in the Bunkhouse Most people use laser pointers for a polish check; Francis prefers high intensity white light, under which unpolished areas look gray.	2010-11 Stellafane Mirror Class Session 2 held on 2011-Nov-06 Polishing in the Bunkhouse Francis also showed us the Acetone Test, a rough test for flatness. A sheet of plate glass is placed in the flat, with a paper shim on one edge. The acetone is dripped onto the flat's exposed surface. It flows under the plate glass, and it's curved flow edge indicate a non-flat surface.

Figuring & Testing in the McGregor

George finished up on Saturday, and Meredith & Rob finished up on Sunday at Dave's house in a little extra-curricular work as they were so close on Saturday. Our other figurers are moving towards completion also.

2010-11 Stellafane Mirror Class Session 2 held on 2011-Nov-06 Figuring & Testing in the McGregor George holds his completed mirror with instructors Phil and Dave.	2010-11 Stellafane Mirror Class Session 2 held on 2011-Nov-06 Figuring & Testing in the McGregor Here's a view of George's mirror in the tester early in the day.	2010-11 Stellafane Mirror Class Session 2 held on 2011-Nov-06 Figuring & Testing in the McGregor Here's a later view of George's mirror after he removed a lot of turned down edge.
2010-11 Stellafane Mirror Class Session 2 held on 2011-Nov-06 Figuring & Testing in the McGregor George holds a certificate for a free mirror coating from Optic Wave Labs with Jay at his side.	2010-11 Stellafane Mirror Class Session 2 held on 2011-Nov-06 Figuring & Testing in the McGregor This thin plastic square was pressed into George's lap to lower the center, so his turned down edge could be attacked by the lap.	2010-11 Stellafane Mirror Class Session 2 held on 2011-Nov-06 Figuring & Testing in the McGregor Depressed about Turned Down Edge? Depress the center of your lap! You can see the lack of center contact with the mirror on the lap. George cured his TDE with this and finished his mirror.
2010-11 Stellafane Mirror Class Session 2 held on 2011-Nov-06 Figuring & Testing in the McGregor Meredith figures; she completed her mirror the next day at a special session at Dave's house.	2010-11 Stellafane Mirror Class Session 2 held on 2011-Nov-06 Figuring & Testing in the McGregor This is what Meredith's mirror looked like late in the day on Saturday, close but not quite done.	2010-11 Stellafane Mirror Class Session 2 held on 2011-Nov-06 Figuring & Testing in the McGregor Instructor Rick does a bit of polishing as does Rob; ROb finished up on Sunday at Dave's house in special session.
2010-11 Stellafane Mirror Class Session 2 held on 2011-Nov-06 Figuring & Testing in the McGregor Jean works on figuring her mirror in the McGregor.	2010-11 Stellafane Mirror Class Session 2 held on 2011-Nov-06 Figuring & Testing in the McGregor Rob & Dick figure - an arm in sling should not slow you down!	2010-11 Stellafane Mirror Class Session 2 held on 2011-Nov-06 Figuring & Testing in the McGregor Deb reads on the bench mid-day at the McGregor.

Bath Interferometer

Paul dug around in his 'junk box' and assembled a Bath Interferometer which he is still improving upon but it worked well enough to produce fringes without much fuss.

2010-11 Stellafane Mirror Class Session 2 held on 2011-Nov-06 Bath Interferometer Paul checks the fringes produced by his Bath Interferometer.

2010-11 Stellafane Mirror Class Session 2 held on 2011-Nov-06 Bath Interferometer The laser and beam splitter assembly.

2010-11 Stellafane Mirror Class Session 2 held on 2011-Nov-06 Bath Interferometer Here is a view of the fringes. Paul says he needs a better mirror to get large fringes. I'm sure he hill be hunting in his junk box for just the right item.

Time out for a Museum Visit

At 1:00 PM, we opened the Telescope Making Museum in the Hartness House for mirror class students to visit. we had a good turnout, and the students enjoyed seeing this unique museum.

2010-11 Stellafane Mirror Class Session 2 held on 2011-Nov-06 Time out for a Museum Visit This sign is above the tunnel at the entrance. You proceed down it to the museum and telescope.	2010-11 Stellafane Mirror Class Session 2 held on 2011-Nov-06 Time out for a Museum Visit Mirror Class people in the front room of the Museum.	2010-11 Stellafane Mirror Class Session 2 held on 2011-Nov-06 Time out for a Museum Visit Mirror Class people in the middle room of the Museum.
2010-11 Stellafane Mirror Class Session 2 held on 2011-Nov-06 Time out for a Museum Visit Mirror Class people in the middle room of the Museum, looking the other way.	2010-11 Stellafane Mirror Class Session 2 held on 2011-Nov-06 Time out for a Museum Visit Amy looks in the eyepiece of the Hartness Turret Telescope.	2010-11 Stellafane Mirror Class Session 2 held on 2011-Nov-06 Time out for a Museum Visit Steve examines the outside of the Hartness Turret Telescope.

Pavilion Improvements

Using our new saw mill, we enclosed the area under the balcony to use for a variety of purposes, but right now it is the grinding area.

2010-11 Stellafane Mirror Class Session 2 held on 2011-Nov-06 Pavilion Improvements The area under the balcony in the Pavilion has been enclosed, and we used this space for grinding this weekend. The scrap lumber has not been cleaned up yet.

2010-11 Stellafane Mirror Class Session 2 held on 2011-Nov-06 Pavilion Improvements John & Jeff set up to saw a very nice piece of blank cherry on the sawmill.